Land use and land cover (LULC) change in tropical regions can cause huge amounts of carbon loss and storage, thus significantly affecting the global climate. Due to the differences in natural and social conditions between regions, it is necessary to explore the correlation mechanism between LULC and carbon storage changes in tropical regions from a broader geographical perspective. This paper takes Hainan Island as the research object, through the integration of the CA-Markov and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) models, based on multi-source data, analyses the dynamics of LULC and carbon storage from 1992 to 2019 and the relationship between the two, and predicts future LULC and carbon storage under different scenarios. The results show that (1) the built-up land area of Hainan Island expanded from 103.59 km² to 574.83 km² from 1992 to 2019, an increase of 454.91%; the area of cropland and shrubland decreased; and the area of forest increased. (2) Carbon storage showed an upward trend during 1992–2000, and a downward trend during 2000–2019. Overall, LULC changes during 1992–2019 reduced carbon storage by about 1.50 Tg. (3) The encroachment of cropland in built-up land areas is the main reason for the reduction of carbon storage. The conversion of shrubland to forest is the main driving force for increasing carbon storage. The increase and decrease of carbon storage have obvious spatial clustering characteristics. (4) In the simulation prediction, the natural trend scenario (NT), built-up land priority scenario (BP) and ecological priority scenario (EP) reduce the carbon storage of Hainan Island, and the rate of decrease is BP> NT > EP. The cropland priority scenario (CP) can increase the LULC carbon storage, and the maximum increase in 2050 can reach 0.79 Tg. This paper supplements and improves the understanding of the correlation between LULC and carbon storage changes in tropical regions, and can provide guidance for the optimization of LULC structure in tropical regions with high economic development from a low-carbon perspective.

Located in China’s Beijing–Tianjin–Hebei region, the Daqing River Basin has a high economic development level. The natural and social conditions within the basin vary greatly, and the spatial configuration of the Production–Living–Ecological Space (PLES) between different sub-regions is unbalanced, with problems and contradictions in the functions of PLES becoming increasingly prominent. This study constructs a PLES classification system for the Daqing River Basin based on multi-period land use data, simulates the future land use evolution of the basin using the Patch-Generating Land Use Simulation (PLUS) model, calculates the coupling degree (CD) coupling coordination degree (CCD) of PLES from 1992 to 2020, and, under the natural trend development scenario (NT), cropland preservation development scenario (CP), and ecological preservation development scenario (EP) of 2030, quantitatively analyses the historical evolution and future direction of the three-life spatial. The results show that: (1) From 1992 to 2020, the area of living space in the Daqing River Basin has increased significantly, while the area of production space and ecological space has decreased significantly. Compared to NT, CP is beneficial to the maintenance of production space, while the EP is beneficial to the maintenance of ecological space. (2) Globally, the CD and the CCD of PLES in the Daqing River Basin show an increasing trend from 1992 to 2010 and a decreasing trend from 2010 to 2020. In 2030, the CD and the CCD of PLES of the three development scenarios decrease significantly compared to 2020; however, the decrease in CP is slight. (3) By region, from 1992 to 2020, the CCD of PLES in the western and eastern parts of the Daqing River Basin increases relatively more, while the central part increases slightly. Compared to 2020, the CCD of PLES in the central part of the Daqing River Basin is predicted to decrease significantly under NT and EP in 2030, while the decrease is slightly less under CP. In all three scenarios, there are some areas where the CCD of PLES increases in the western areas. This study highlights the internal variability of the spatial evolution of PLES in the basin and focuses on the impact of different future development scenarios on the spatial changes of PLES, which can offer an enlightenment for high-quality development and sustainable territorial spatial planning in the Daqing River Basin.

In order to understand the driving characteristics of electric heavy-duty trucks in practical application scenarios and promote their usage to replace diesel trucks, this study analyzed the actual usage of electric and diesel heavy-duty trucks in a steel factory based on vehicle-monitoring data and remote online monitoring data and estimated the emission reduction potential of the application of electric trucks by using a mileage-based method and the greenhouse gas emission model. The results showed that the electric heavy-duty trucks in the steel factory mostly operated for over 14 h, with a vehicle kilometers traveled (VKT) of 50–300 km each day, which could meet most of the demands of the transportation of the steel industry. The average daily energy consumption for most trucks falls within the range of 210–230 kWh/100 km, with higher consumption in winter than in summer, which can save approximately 18–26% in operating costs compared with diesel trucks. It is estimated that the usage of these electric heavy-duty trucks can achieve an annual reduction of 115.8 tons of NO_x emissions, 0.7 tons of PM emissions, and 18,000 tons of CO₂ emissions. To further promote the application of electric heavy-duty trucks in China, several policy suggestions, such as introducing priority road-right policies, promoting vehicle and battery leasing markets, and exempting zero-emission vehicles during heavy pollution days, were proposed.